The canning industry has long desired a method for preserving fresh produce, e.g. fruits and vegetables, for extended periods of time after harvesting so that canning and/or other further processing can be conducted when desired. However, in accordance with the present state of the art canneries are required to utilize an inordinate amount of labor and equipment to ensure that the freshly harvested produce is quickly processed shortly after harvesting and before the product deteriorates in quality.
Typically, shortly after the harvesting season is over, the canneries are shut down and are no longer productive. Consequently, overall costs for the canning industry are greatly increased.
Prior suggestions for preserving freshly harvested produce before canning have been unacceptable for a variety of reasons. For example, although modified or controlled atmosphere post-harvest storage techniques have been found useful for extending the storage life of fruits and vegetables at 32.degree. F. for up to about three to six weeks, such techniques have generally only been effectively applied to certain varieties of fruits and vegetables.
Alternatively, it has been suggested to aseptically process the harvested fruit or temporarily process fruit into large cans which are cut open at a later time, so that the fruit can be reprocessed into smaller cans for distribution to the consumer. However, because the texture of the fruit is altered (e.g., softened) during the thermal processing required by these methods, the treated fruit cannot satisfactorily withstand further processing, e.g. canning. Also the cut-open cans must be handled and disposed of in an acceptable manner.
It has also been proposed to subject harvested fruit to block freezing or individual quick freezing ("IQF"). However, because the structural integrity of the block frozen fruit is not maintained during thawing, the fruit is rendered unsuitable for canning. Moreover, IQF methods may be found objectionable because of the high capital costs involved.